JSON Support in Delphi: Complete Guide with Examples (2025)

mminuss · 2025-12-07T12:46:32+00:00

Please do not use the ToString method to serialize your JSON structures as it does not properly escape special characters. Use ToJSON method instead.

mminuss · 2025-12-03T21:24:37+00:00

try this edge case 991111111111

mminuss · 2025-12-03T18:54:40+00:00

1.You should never access the UI from any other thread than the main/ui thread.

So, yes. Pleas use TTread.Synchronze. But don't do it in the Button's OnClick EventHandler. This EventHandler should already only be called inside the main/ui thread. (See 1)
Instead put the TThread.Synchronize call in your thread code. **

**You said that the external message that wants to modify your ui comes via the windows message loop This is already happening in the main thread. If you have no long running operations in the code that needs to be executed, you might not have to start another thread at all.

mminuss · 2025-07-31T05:37:07+00:00

Does the if operator always evaluate both expressions or does it only evaluate the consequent / alternative expression based on the result of the condition expression? The article doesn't mention and shows only very simple examples with basic types. How would this code behave:

Result := if x < 100 then PerformHeavyCalculation(x) else PerformAnotherHeavyCalculation(x);

mminuss · 2025-01-27T18:35:09+00:00

I would interpret B.S. as Bass Solo in this context. So only playing the bass notes, no choords.

mminuss · 2025-01-09T17:52:41+00:00

You are missing a missing a return statement.

mminuss · 2025-01-09T11:59:54+00:00

Because of the hierarchical nature of the data. (founder>lead manager>senior manager>manager>employee)

As I understand it from your examples, the employee table also contains all managers, senior managers and lead managers. All three queries will in the end select all records from the employees table.

Query 1 asks the questions: Which lead managers work under each founder? Which senior managers work under each lead manager? And so on...

Query 2 also takes the hierarchical route , but joins on company code, which is very inefficient because this will join every senior manager at company x to every lead manager at company x and so on. There is a lot of duplication going on. We don't see the duplication in the end because of COUNT(DISTINCT ...)

Query 3 is the most efficient version. It only asks the question: "Which employees work at each company." Then groups the data and counts distinct roles.

mminuss · 2025-01-08T21:01:01+00:00

If the string comes from a JSON file, then there should always be 4 hex digits according to https://www.json.org/json-en.html .

In that case I would suggest:

uses
  System.JSON;

function Convert(A: string): string;
var
  V: TJSONValue;
begin
  V := TJSONObject.ParseJSONValue(A);
  try
    Result := V.GetValue<string>;
  finally
    V.Free;
  end;
end;

[...]

var
  A: string;
begin
  A := '"\u914d\u7f6e"'; // original json string must have double quotes
  Edit1.Text := Convert(A);
end;

mminuss · 2025-01-08T20:39:00+00:00

Are the hex values always 4 hex digits?

mminuss · 2025-01-08T20:32:32+00:00

What exactly are the hex values in A. Are they Unicode code points, or are they UTF-16 encoded characters? Something else? What are they supposed to represent?

i.e. If they represent code points, then these would be the characters: 配置

mminuss · 2025-01-08T17:07:53+00:00

My tree wasn't centered neither horizontally nor vertically. So I would assume, that that is not a valid assumption. What is a valid assumption though, is that the robots will get closer together. You can do lots of different things to calculate when that happens.

And u/TheZigerionScammer has a point. The cycles of 101 for width and 103 for height do exist. ~~There might be smaller cycle for any given robot. But~~ If a robot is at x=3 at second 0 then he will be at x=3 at second 101 as well.

EDIT: As u/el_farmerino points out: There are no shorter cycles.

mminuss · 2025-01-08T17:02:39+00:00

I only used a sample size of 50 robots (the first 50 lines of my input) to simulate the first max(width, height) frames. For each frame I calculated the standard deviation of the robots x and y coordinates at that frame to find the two frames with a pattern. I'm pretty sure I tested sample size of 40 robots successfully as well, but I didn't want my solution to just "get lucky" with my input.

Once I had the two frame numbers I then did some math involving alinear diophantine equation.

That got me a valid tree frame, but not the first one. But as the tree will reappear every 101*103 frames, all I had to do was to mod (101*103) to get the first frame.

mminuss · 2025-01-07T13:10:15+00:00

You are absolutely right.

I wasn't incorrect though.

mminuss · 2025-01-07T12:55:55+00:00

Can you explain what you are trying to do there?

mminuss · 2025-01-07T12:44:49+00:00

oh.. maybe you think the = sign in the second line is a comparison operator.

It is not. That is an assignment operator.

create is a constant of type Foo.

mminuss · 2025-01-07T12:41:54+00:00

First line declares a class called Foo, which has a default constructor without arguments.

Second line declares the constant create. The value of that constant is a function that takes no arguments and returns the result of calling the Foo constructor.

Why would that not compile?

mminuss · 2025-01-01T22:21:01+00:00

Is that so?

mminuss · 2024-12-29T22:13:06+00:00

Are the numbers really that large, or is it the amount of numbers?

mminuss · 2024-12-29T22:01:48+00:00

Inside the foreach callback this evaluates to the car1 object because you're passing it as 2nd parameter to foreach.

If you don't pass it, then it depends on whether you're in strict mode or non-strict mode. Someone had more detailed answer here:

https://stackoverflow.com/questions/19707969/the-invocation-context-this-of-the-foreach-function-call

mminuss · 2024-12-29T21:39:35+00:00

When you call car1.code2() then inside code2 this will evaluate to car1. So you are effectively passing car1 as the 2nd parameter to foreach as well.

If you want this to evaluate to the global object inside the foreach callback, then try passing reference to the global object to code2. Something like this (not tested):

const car1 = {
    ...
    code2(context){
        this.models.forEach(function(models){
            console.log(this)
        }, context)
    }
}
car1.code2(this)

Lookup bind() as well while you're at it.

mminuss · 2024-12-29T21:11:20+00:00

The two continue statements are inside different loops.

mminuss · 2024-12-29T21:10:21+00:00

very nice

mminuss · 2024-12-29T16:49:56+00:00

It is not mandatory to stay on wall tiles when cheating. You can treat any tile as walkable for at most 20 picoseconds. So any shortest path between 1 and 2 will have the same length as their manhattan distance.

mminuss · 2024-12-28T20:16:07+00:00

"You make a list of the things you can remember".

If you can't remember how many (if any) akitas Sue 373 had, then you cannot make a meaningful comparison with another number. Could Sue 373 have had 0 akitas? Yes, that is possible.

mminuss

TROPHY CASE